Container closure and method of making



Feb. 9, 1937. J. w. PERRY CONTAINER CLOSURE AND METHOD, OF MAKING Filed Jan. 22, 1952 '5 F g-5 v m i i .4 lln mh II IHW 11 I 1. I MM I i 6 Fig.4

- Inventor dameship Patented Feb. 9, 1937 UNITED STATES CONTAINER CLOSURE AND METHOD OF MAKING James W.

Perry. Hartford, Conn... assignor to Oolts Patent Fire Arms Manufacturing 00., Hartford, Conn., a corporation of Connecticut Application January 22, 1932, Serial No. 588,177

4 Claims.

The invention relates particularly to a container closure molded from plastic material and having a liner therein, and it further relates to the method of making a. container closure and liner assembly.

Various means have been heretofore proposed and used for holding liners in container closures.

In some instances the liners have been merely pressed in place being held solely by friction; in other instances the body of the closure has been provided with special retaining means adapted to engage and hold the liner; and in other instances the liners have been glued or cemented in place. Each of the foregoing means is useful and is efiective and satisfactory with certain classes of liners and for certain classes of service, but each of these means is subject to one or more objections. The objection most frequently encountered is that the liner is not securely held and may fall out during preliminary handling and shipment of the closure and during use of the closure upon a container. Even when special holding means are provided for the liner, shrinkage or distortion of the liners may cause them to become disengaged. The expense of cementing liners in place is large, and it frequently happens that the cement is chemically at-,

tacked bythe contents of the container, being disintegrated and thus releasing the liner.

liner is positively held in place so that removal is entirely impossible, and this is accomplished.

- 5 or the like on the body of the closure, and without providing any separate cement or adhesive. The material constituting the body of the closure is'utilized as an adhesive for holding the liner in place. 40 In the accompanying'drawing I have shown a closure and liner assembly embodying the present invention and I have also illustrated the steps constituting the method by which the closure and liner assembly is made. It will be under- 45 stood, however, that the drawing is intended for illustrative purposes only and is not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specificationbeing relied upon for that purpose. 50 Of the drawing:

Fig. l is an enlarged side view of a bottle cap or container 'closure embodying the invention, a portion of the cap at one side being broken away to show the liner.

In accordance with the present invention the appears prior to being assembled with the closure.

Fig. 3 is a combined vertical sectional and elevational view showing the mold in which is carried out the steps constituting my improved 5 method, the mold parts being in their separated or open positions.

Fig. 4 is a view similar to Fig. 3, but showing the mold parts in their closed positions.

Fig. 5 is a view similar to Fig. 2 but showing 0 a slightly different embodiment of the invention.

Referring to the drawing, I represents a-container closure as an entirety and I have shown a closure of the cap type. The closure, whether of the cap type, or of some other type, is molded from an artificial resin or other plastic material. The external contour or configuration of the closure or cap I is immaterial insofar as the present invention is concerned and I- have therefore shown a bottle cap of conventional design.

The closure I is preferably provided with suitable threads 2 which are adapted to engage corresponding threads on the container with which the closure is to be used. When the closure is in the form of a cap the threads 2 are internal threads. The closure I is provided with a flat top surface or wall 3 which contacts directly with a thin flat liner 4. When the closure is in the form of a cap the liner 4 is a disc.-

It will be observed that the liner 4 is held in place in the closure I solely by the adhesive action of the closure material at the said top S111- face -3. This is made possible by making the liner from a slightly porous material having a surface of such charatcer as to be adapted to unite with or adhere to the closure material. Obviously, were it not for the adhesive action, the liner would be freely separable from the cap, as it is not' otherwise held. The adhesive action is brought about by so placing and holding the liner 40 that it is engaged by the material of the closure during the process of molding and while the said material is in a fluid or semi-fluid condition. The material while in such fluid or semi-fluid condition acts as an adhesive and becomes firmly united with the porous material constituting the liner 4 by entering the pores thereof. As the material of theclosure sets and hardensits adhesive function is retained, and the liner is thus held in place without the use of any separate adhesive and without dependence upon any special projections or the like on the closure.

In Fig. 3 I have shown the mold by means of which the combined container closure and liner assembly is made, the upper part 5 of the mold being shown separated from the lower part 0. It will be' observed that the upper part 5 of the mold is provided with a cavity 1 shaped to determine the exterior contour of the completed cap and that the lower part 8 is provided with a pinor plug U shaped to determine the interior contour of the cap. The'said plug 8 is provided with external threads 9 which are positioned and shaped to produce the required internal threads 2 in the completed cap.

The first step in the procedure for making the completed article is to place a liner 4 in a definite predetermined relation to the parts of the mold, so that upon the closing of the mold the liner will assume its proper relationship with the closure which is being molded. With a mold having I the parts constructed and arranged as described, the liner4 isplaced on topofthe plug 8 and the shape.

moldable material, preferably in the form of a briquette A, is placed on top of the liner. The mold is then closed in the usual way by moving the upper part I downward with respect to the lower part 6, thus compressing the moldable material and causing it to assume the required When the moldable adaptedto be molded under heat and pressure, it will be understood that the mold parts are heated in any usual or preferred way and that the mold is closed by means .of a press which is adapted to the required amount of pressure. Under these conditions the moldable material, while initially solid, momentarily a liquid or semi-liquid condition, and while in this condition it adheres to and unites with the material constituting the liner 4. At the conclusion of the molding operation the mold parts are in the relative pomtion's shown in Fig. 4.and the cap I has been completely molded with the porous material at the surface I thereof rigidly adhering to'the liner 4 so as to positively hold it in place.

The mold can then be opened by raising the top part thereof, and the completed closure and liner.

assembly can be removed from the plug I b unscrewing it in,the usual way.

Preferably in order that the liner 4 may be conveniently located and held in central position on the plug 0, and in order that other desirable results may be obtained, the plug 8 is provided with anupstanding annular rib ll of such diameter as to provide a suitable shallow recess within which the liner 4 can be placed. It will be understood that the rib II is relatively narrow, thus enabling the liner to beef sumcient size .to engage and effectively seal the mouth of the container.- The rib Ill not only. locates and prelimiharily holds the liner, but it also serves to prevent any distortion or spreading of the liner during molding. Without' means such as the rib it for holding the liner there would be a tendency for the moldable material to adhere to the liner while still flowing, thus spreading the liner or even tearingit apart.

the periphery of the jlinerand the adjacent It will be apparent that the rib it, when made as deepas shown in Figs. 3 and'4, produces a relatively deep groove i I in the completed closure. and also provides a narrowv space between wall of the closure. The annular liner retaining ring on the .plug I may. under some circumstances, be considerably shallower than thatshown at ll, particularly if the ratherdeep groove ii in the cap is found to be objectionable. In Fig. 5 I have shown a cap l made with a mold having a considerably shallower rib, the said cap having, a groove I I with a depth no greater than the thicknesslof the liner.

I have already stated that the liner 4 is made from a material having a surface of such character as to be adapted to unite with or adhere to the material of the closure. I do not narrowly limit myself as concerns the character .of the liner material, but I have found that certain varieties of wood constitute a highly satisfactory material for this purpose. Balsa wood is regarded as'particularly suitable, not only because of its capability of adhering to the liner, but also because: of its compressibility and resiliency and its other advantageous qualities as a liner material. A liner made of wood, particularly balsa wood. is impervious to the e of liquids faces of the liner.

material is a material I What I claim is:

l. A container closure and liner assembly comprising in combination, a molded closure adapted to engage suitable retaining means on the container, and a slightly porous liner carried by the closure and adapted to seal the mouth of the container, the material of the closure adjacent the liner extending into the pores of the liner to hold it in place and the said llnerbeing otherwise freely separable.

2. A container closure and hner assembly comfreely separable;

3; A container closure and liner assembly comprising in combination, a molded closure adapted to enage suitable retaining means on the con-v prising in combination, a molded closure of the cap type. adapted to engage suitable retaining means on the container, and a slight y porous liner carried by the closure and adapted to-seal the mouth of the container, the said liner being free from peripheral engagement with the closure-and the material of the closure adJacent the liner ex-' 1 tending into. the pores of the liner to hold it in place and the said liner being otherwise, freely removable.

4. The herein described method of making an assembly of a container closure of the cap type and a liner, which comprises placing a fiat slightly porous liner and a suitable quantity of moldable material in a suitably shaped mold with the liner at a definite predetermined position in'immediate proximity to that portion of the mold which determines the interior contour of the closure, and closing the moldand thereby applying pressure to the said material to effect molding of the closure with the lower surface and also the periphery of the liner free from engagement with any part of the closure, the material constituting the top wall of the closure entering the pores of the liner ing as an adhesive to hold the liner in. place.

' JAMES w. PERRY.

' and engaging the upper surface thereof and act-. j 

